Why recording LOG with an 8bit codec is most probably going to get you in trouble.

[Oliver Daniel]

I'm surprised at the lack of chat about how lighting affects color rendering. 

Yes, there are a lot of sloppy grades out there for the A7S, but how many of these people used the ISO function to digitally enhance the lighting on their subject? Probably many. 

I did a test with the A7S with a model and used the ISO to expose the image. Then I did the same but used 2 LED 1x1 and a Dedolight as a kick instead of boosting ISO. Surprise, surprise - the colour and overall image quality was a million times better! 

While this is blindingly obvious, I see a lot of critique on the quality of camera footage from tests, yet these tests didn't utilise the simple practice of using proper light sources. So when we say LOG is crap in 8bit, what footage are we talking about? I expect it will look like a cocktail of sick, shot at 80,000 ISO on the A7S. Also how many know how to expose a log image properly? It's very tricky until you "get it". I get it wrong often, lots always to learn. 

My opinion, 8 bit is mostly fine for log - just don't expect it to work wonders in certain conditions. Use decent light sources, expose properly, set up the WB correctly and results should be great! Canon has better log than Sony (based on color) and the major difference with 10bit for me are smoother gradients, deeper colors and greater tonality.  

[cpc]

and the major difference with 10bit for me are smoother gradients, deeper colors and greater tonality.  

Not enough of a difference for you to care then, I presume?

[animan]

I'm not confusing the two, I'm saying that if you;re shooting log on 8bit cameras it should be in order to maintain the greatest dynamic range on your camera files, for post adjustment of contrast, Not colour.  

Log or not,  if your WB is too far away from the end result you're in trouble.  If i want a teal grade I'd set wb to a lower kelvin number and increase the bias towards green/blue.  if i want a warm grade I'll go the opposite way.  

 

 

fair enough, but still, theres more to grading than saturation and colour temp.

[Oliver Daniel]

Not enough of a difference for you to care then, I presume?

Actually 8bit and 10bit is inferior to my needs. I need at least 64bit color, 25 stops dynamic range, 16,000,000 ISO and a very compact full frame 14-600mm IS lens with 20 aspherical elements and F0.001 aperture. I'll just light the images in post. Images will surely look great based on these specs! 

[Nikkor]

16K , double sensor with split lens so you have depth information which makes lighting in post more effective. Oh wait, just render everything, download some good actors, download a script and let the computer do the rest.

[Nick Hughes]

Yes, there are a lot of sloppy grades out there for the A7S, but how many of these people used the ISO function to digitally enhance the lighting on their subject? Probably many. 

Exactly. Color exists because of specific wavelengths of light being reflected off surfaces. Color doesn't exist without light, so if there is less light, there's going to be less color. If you're shooting a scene at 52,000 ISO, of course the colors will look weird because they literally aren't there!

(physics people please correct me if I'm wrong about this)

[Oliver Daniel]

Exactly. Color exists because of specific wavelengths of light being reflected off surfaces. Color doesn't exist without light, so if there is less light, there's going to be less color. If you're shooting a scene at 52,000 ISO, of course the colors will look weird because they literally aren't there!

(physics people please correct me if I'm wrong about this)

Exactly. 

This is mostly why cameras like the A7S get over-criticised for color. A lot of people are boosting color that isn't accurate color with ISO. Swap that ISO for lighting and you will notice a massive difference. It sounds so kinda obvious. 

Low light is a very useful tool with trade-offs in image quality. But you are not going to get anywhere with any type of log if you are relying on the ISO as your main light source. There is a reason why cinema cameras aren't low light cameras, because the camera produces it's best image with added light, not digitally enhanced light. 

[cpc]

Exactly. Color exists because of specific wavelengths of light being reflected off surfaces. Color doesn't exist without light, so if there is less light, there's going to be less color. If you're shooting a scene at 52,000 ISO, of course the colors will look weird because they literally aren't there!

(physics people please correct me if I'm wrong about this)

 

This only applies to humans. We simply don't see color well at low light levels because of the way human vision works.

Cameras don't have this problem. What you perceive as lack of color in low light captured images is for a couple of reasons:

1) In naturally occuring low light situations the spectrum of the light is often overly monochromatic. For example, dusk light has lots of blue and tungsten has a strong red component. This offsets the image toward monochromatic.

2) Overly noisy image.

 

Anyhow, the A7s s-log2 lacks tonal precision even when shot at its minimal ISO (which is 3200) and overexposed for healthier signal.

[AaronChicago]

If anyone is interested in trying out an 8 bit S Log 3 video from the FS7 download it below. I shot this awhile back but finally am able to release screen shots, etc. Shot at 3200k.

https://www.dropbox.com/s/gsn0opn4zxkl7t0/Slog3.mov?dl=0

 

 

Edit: shit i just learned it is 10bit. Shows what i know. 

[TheRenaissanceMan]

If the A7S and other low-end Sonys had SLOG3 and SGamut3.cine, I don't think we'd see these huge problems with color. Tonal precision would remain low, but at least with the new SGamut we'd have the option of the Type A Look Profile in Resolve that is specifically designed to emulate the Alexa's color.